I’m a 50-year-old man. I’ve been married to the same woman for 18 years and have never cheated. I don’t believe I ever will. But that doesn’t mean I don’t notice pretty girls. I do. I’m a man. It’s natural.

At our core, all humans are just animals. All animals reproduce to keep their respective species going. The desire to reproduce is coded into our DNA. The mere thought of having sex is simply our biological desire to advance the species.

Female humans require nine months to gestate offspring. Men take seconds to fertilize the female’s egg. Even if women were fertile from 18 until 48, the most children she could yield would be something like 30. If a man were to have sex just once every day with a different fertile woman over that same timeframe, he could sire 10,950 children. Therefore, male humans are better equipped than females to keep the species thriving.

Heterosexual men are attracted to women. But not just any women – young women. And it’s not because of muscle tone or curves in the right places, it’s because, biologically, men see younger women as more fertile. That’s why we look. Sure, we can point to specific female attributes as the reason men are attracted to women, but they’re only relevant attributes because of our core biology. God’s no dummy.

Our inescapable biology is why Playboy has been a company since 1953. It’s also why magazines like Playboy cast younger women instead of women in their 40s. Men are programmed to ‘want’ sex with younger women as a way to keep the species going. Madison Avenue knows this too. That’s why the skimpier the outfit of the pretty, young woman in the ad for sneakers – the more likely men will notice the the ad. It’s also why on Twitter you don’t see many spam accounts featuring avatars of well-endowed men with bios reading, “When I get down on my knees, it’s not to pray.” Yes, at our core, we’re all just animals driven by appetites. It’s our great fallibility. And it’s one of the main reasons men cheat on their wives with younger women.

But there is hope. Unlike elk, humans have thumbs. And consciences. Now before any animal people get crazy – I’m not saying that animals don’t have consciences. I’m saying that human brains have evolved so that we understand our own instincts and appetites and can elect to control them when we fall in love. The idea of monogamy might not be exclusive to humans, but it’s clearly more prevalent. For some of us, anyway.

I’m a 50-year-old man who has been married to the same woman for 18 years. We have two daughters together who will likely be my only contributions to our species. And that’s ok – because I love my wife and am willing to suppress my instincts in order to enjoy the fruits of a monogamous relationship. However, I’ll likely always notice pretty girls. Because I’m just a man. And all men are animals.

Jim Mitchem

Married 23 years (to the same woman). Three children (I won’t be making more). I’ve never cheated (and don’t imagine that I will). I, too, “am willing to suppress my instincts in order to enjoy the fruits of a monogamous relationship.”

I, too, will “likely always notice pretty girls.” I will notice them discretely. As I’ve told my wife of 23 years, “Marrying you didn’t make me gay.”